Air pressure-actuated double-acting diaphragm pump

ABSTRACT

A double acting pressure-actuated diaphragm pump comprising first and second housings each containing a pump diaphragm. An intermediate casing is provided for interconnecting the housings and containing common actuating means for the pump diaphragms. The first and second housings are mounted on a track structure with subassembly sections of the housings being retractable thereon to allow for selective inspection of the respective diaphragm portions of the first and second housings.

111 States atent 1191 11 3984933 Schallll Nov. 19, 1974 AIRPRESSURE-ACTUATED 3,364,871 1/1968 Wilson 417/454 DUUBLE'ACTINGDIAPHRAGM M FOREIGN PATENTS OR APPLICATIONS [75] Inventor: small,Stamford Com 101,233 9/1896 Germany 417/454 [73] Assignee: Don-OliverIncorporated, Stamford,

Conn. Primary Examiner-William L. Freeh Assistant Examiner-Leonard Smith[22] Filed 1974 Attorney, Agent, or Firm-Burtsell J. Kearns; [21] Appl.No: 456,110 Theodore M. Jablon Related US. Application Data [60]Division srsei. NO. 365936, June 1, 1973, which is [57] ABSTRACT acontinuation of S61. NO. July 12, A double acting pressure actuateddiaphragm pump abandoned comprising first and second housings eachcontaining a pump diaphragm. An intermediate casing is pro- {g 8 2354vided for interconnecting the housings and containing I n commonactuating means for the p p di p g [58] Field of Search 117/395 92/128The first and second housings are mounted on a track 56 f structure withsubassembly sections of the housings 1 Re erences cued being retractablethereon to allow for selective inspec- UNITED STATES PATENTS tion of therespective diaphragm portions of the first 151,409 5/1874 Markle 417/454and second housings. l,64l.7l7 9/l927 Welter 417/454 1,848,441 3/1932Stephens 92/128 x 7 Claims, 13 Drawing PATENTE; PM 1 91974 sum 03 or 10PATENTEL 59V 1 91974 3.849.033

' sum 08 0F 10 FIG. I0

AIR PRESSURE-ACTUATED DOUBLE-ACTING DIAPHRAGM PUMP This is a division ofapplication Ser. No. 365,936, filed June I, 1973 which is a continuationof Ser. No. 161,465 filed July 12, 1971, now abandoned.

This invention relates to fluid pressure-actuated diaphragm pumps. Insuch pumps, the diaphragm is stresscompensated during the pumping orpump delivery stroke, because the pressure of a fluid medium or air isapplied to the diaphragm to move the same against a pumping head.

A general object of this invention is to provide an improvedfluid-pressure actuated pump capable of pumping effectively against anegative suction head. To this end, the invention proposes to utilizethe fluid pressure medium as a positive means for effecting apressureassisted return or pump suction stroke.

More in particular, a main object is to provide a high capacitydouble-acting diaphragm pump wherein the pumping stroke of one diaphragmcoincides with the suction stroke of another diaphragm, and vice versa,and wherein a pressure fluid medium is applied not only for effectingthe pump delivery stroke against a pumping head, but also for effectingthe return or suction stroke against a negative suction head, with aneffective actuating or control system provided for maintaining thepumping cycle.

Thus, it is a more specific object to provide a control system formaintaining the pumping cycle, which is simple, positive acting, andreadily accessible as well as easy to adjust, preferably comprisingstandard sealed component actuating units that are individuallyavailable, and can be readily assembled and connected to the pump, andwhich when in place are readily accessible for inspection andadjustment.

Another object is that the control system should have simple means foradjusting the length and frequency of the pumping stroke, even while thepump is in operation.

To attain the foregoing objectives, the invention provides adouble-acting diaphragm pump which comprises a pair of cooperatingdiaphragm pump units or component pumps coaxially arranged and connectedrigidly to one another. Each component pump has a diaphragm dividing thepump housing into a pumpingor pump delivery chamber provided with avalved intakeor suction connection and with a valved dischargeconnection, and a pump actuating chamber provided with a connection forsupplying a fluid pressure medium, as

well as for venting the chamber.

The two component pumps are spaced from each other by an intermediate orinterposed coaxial connecting member rigidly flange connected to thepumps, with the two actuating chambers facing each other, and the twopumping chambers facing in opposite directions.

Each of the diaphragms has a central rigid portion as in the form of apair of circular clamping plates. An actuating rod rigidly interconnectsthe centers of the two diaphragms, so that the pumping stroke of the onediaphragm will coincide with the pump suction or pump filling stroke ofthe other diaphragm, and vice versa. The connecting rod islongitudinally guided in the interposed connecting member, and insealing relationship to either one of the adjacent pump-actuatingchambers.

A control or actuating valve system for moving the diaphragms throughthe pumping cycle, communicates with the two actuating chambers, and hasa pressure fluid supply connection. A control member when moved to oneposition causes the control system to admit pressure fluid into thefirst actuating chamber, while allowing the second actuating chamber tobe vented, and when moved to the opposite position causes said system toadmit pressure fluid into said second actuating chamber, while allowingthe first actuating chamber to be vented. The movement of the con trolmember between end positions is effected by the reciprocating movementsof the diaphragm assembly.

In a preferred embodiment, an auxiliary or pilot valve unit having aplug valve member, is mounted on said connecting member of the pumpstructure. The pilot plug valve member through air pressure actuates theplug valve member of a main control valve unit which in turn admits airpressure to the actuating chambers in alternation. The pilot plug valvemember is reciprocated by the movements of the diaphragm assembly.

Features of the invention lie in the valve arrangement of the controlsystem, as well as in the construction and arrangement of the means foractuating the control system from the reciprocations of the diaphragmassembly.

Other features lie in the relationship of parts, and in the manner oftheir assembly to constitute the pump unit, in such a way thatinspection or replacement of the diaphragm is facilitated, without theneed to disconnect the pump intake and pump delivery connections.

As this invention may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, the presentembodiment is illustrative and not restrictive. The scope of theinvention is defined by the appended claims rather than by thedescription preceding them, and all embodiments which fall within themeaning and range of equivalency of the claims are therefore intended tobe embraced by those claims.

FIGS. 1 and 2 schematically illustrate the pumping cycle of adouble-acting diaphragm pump, showing one embodiment of the valvearrangement in the control system.

FIG. 3 is an enlarged fragmentary side view of the intermediate sectionof the pump structure, showing its relationship to the control system,exemplifying a pair of pusher pins for actuating the system from themovements of the diaphragm assembly.

FIG. 4 is a further enlarged longitudinal sectional detail view of oneof the pusher pins, including means for sealingly mounting the same inthe associated pump actuating chamber.

FIG. 5 and 6 schematically illustrate the pumping cycle corresponding toFIGS. 1 and 2 respectively, showing another embodiment of the valvearrangement.

FIG. 7 schematically illustrates a pump control system similar to FIGS.1 and 2, with other motion transmitting means effective between thediaphragm assembly and control system.

FIG. 8 is a cross-sectional view taken on line 8-8 in FIG. 7.

FIG. 9 is a side view of the pump structure and pipe assembly,structrally more fully implemented.

FIG. 10 is an end view taken on line 10-10 of the assembly of FIG. 9.

FIG. 11 is a plan view taken on line 11-11 of the assembly in FIG. 9.

FIG. 12 is a side view of the pump structure, supported on tracks,illustrating the feature of accessability of diaphragms.

FIG. 13 is an end view taken on line 13-13 in FIG. 12.

A fluid pressure-actuated double-acting diaphragm pump in the sense ofthis invention is a pump wherein two pump bodies are rigidlyinterconnected in coaxial relationship. A diaphragm divides the housingof each pump body into a pumping chamber and pump actuating chamber. Anactuating rod interconnects the centers of the two diaphragms so that,when a fluid pressure medium or air pressure is admitted alternatinglyinto the actuating chambers, the pump filling stroke of one diaphragmwill coincide with the pump delivery stroke of the other diaphragm. Acontrol system timed by the reciprocations of the diaphragms andactuating rod admits the fluid pressure medium into the actuatingchambers in a manner to maintain the continuity of the pumping cycle orpumping operation.

According to the several embodiments herein shown, this double-actingpump is equipped with a control system wherein a control member ismovable to one position causing the pressure fluid to be admitted intoone of the actuating chambers, while the other actuating chamber isbeing vented, and movable to the opposite position causing therespective flow directions to be reversed. Motion transmitting means areprovided for actuating said control member by the reciprocations of thediaphragms and actuating rod.

Referring to the embodiment of FIGS. 1 & 2, the pump structure itselfcomprises a pair of pump bodies 10 and 11, and a flanged connectingmember 12 of the length L rigidly interconnecting the pump bodies incoaxial and symmetrical relationship to one another. The pump housing ofthe first pump body 10 consists of two housing sections 13 and 14 boltedtogether, and having confined between a first diaphragm 15 dividing thishousing ino a pumping or pump delivery chamber 16 and a pump actuatingchamber 17. The pumping chamber has an intake connection 18 providedwith a check valve unit 19, and a discharge connection 20 provided witha check valve 21.

Similarly, the pump housing of the second pump body 11 comprising twohousing sections 22 and 23 having confined between them a seconddiaphragm 24 dividing this housing into a pumping chamber 25 and a pumpactuating chamber 26. The pumping chamber has an intake connection 27provided with intake valve 28, and a discharge connection 29 providedwith check valve 30.

A common pump intake 31 is provided for the two intake'connections l8and 27, while a common pump discharge 32 is provided for two dischargeconnections 20 and 29.

Each diaphragm has a central opening 33 provided with an annular bead orbeaded edge portion 34 tightly secured between a pair of circularclamping plates 35 and 36. The centers of the two pairs of clampingplates in turn are rigidly interconnected by an actuating rod 37 thelongitudinal reciprocating movement of which is guided in a pair ofbearings 38 and 39 located in the respective ends of the intermediateconnecting member 12. These bearings are provided with pressure seals 38and 39 respectively, effective together with a sealing ring 39" againstthe pump actuating air pressure to be applied to the actuating chambers17 and 26. Each end of the connecting member 12 has a flange connection40 with the adjoining pump housing section adjacent to the respectiveactuating chamber.

A control system will admit air pressure to the actuating chambers inalternation, so that the delivery stroke of one diaphragm will coincidewith the pump intake stroke of the other diaphragm.

One embodiment of such a control system for maintaining the pumpingcycle is as follows by reference to FIGS. 1 and 2 illustrating therespective phases of the pumping cycle:

This control system comprises a main control valve unit v-1 operable toadmit air pressure to the respective actuating chambers, and anauxiliary or pilot valve unit V-2 controlling the operation of the mainvalve unit, and in turn actuated by the reciprocation of the diaphragmsand actuating rod.

The control valve unit V-l is in the form of a plug valve unit having avalve housing 41 operatively connected to the two actuating chambers byway of pipe conduits 42 and 43 respectively. This valve housing has anair pressure supply connection 44 at the center, communicating with apair of branch passages 44 and 44" in the housing. A pair of ventconnections 45 and 46 are provided at the ends of this valve housing. Aplug valve member 47 is longitudinally shiftable in the valve housing,so that when moved to the right hand end position shown in FIG. 1, itcloses branch passage 44" while admitting air pressure into the lefthand actuating chamber 17 from the supply connection 44 through passage44 in the housing, and from there through pipe 42 into the actuatingchamber, all as indicated by the path of flow arrows A-l. Simultaneouslywith the closing of branch passage 44", the plug valve member opens avent connection to the other actuating chamber 26, as indicated by thepath of flow arrows A-2, namely by way of pipe 43 leading to the valvehousing, and vent 46 leading from the valve housing to the atmosphere.

Thus, air pressure will move the diaphragm 15 through the pump deliverystroke, as indicated by the path of flow arrows A-3 through thedischarge check valve unit 21. The concurrent pump filling stroke ofdiaphragm 24 is indicated by the path of flow arrows A-4, through theintake check valve 28.

The main plug valve member 47 when shifted to the FIG. 2 position,closes the branch passage 44, while admitting air pressure into theright hand actuating chamber 26, supplied from pipe 44 through branchpassage 44" of the valve housing, and then into the actuating chamber26, all as indicated by the path of flow arrows A-S. Simultaneously withthe closing of branch passage 44" the plug valve member opens a ventconnection to the left hand actuating chamber 17, as indicated by thepath of flow arrows A-6, this by way of pipe 42 leading to the valvehousing, and vent 45 from the valve housing to the atmosphere. In thiscondition, air pressure will move the diaphragm 24 through the pumpdelivery stroke, with pump delivery indicated by flow arrows A-7,through the delivery check valve 30. The concurrent pump filling strokeof diaphragm 15 is indicated by the path of flow arrows A-8, through theintake check valve 119.

The foregoing operation of the main plug valve unit Vll is controlled bythe pilot valve unit V-2 which causes the shifting of the main plugvalve member 47, but which itself is actuated by the reciprocations ofthe diaphragms and actuating rod.

The pilot valve unit has a plug valve member 48 ex tendingco-directional with the actuating rod, and longitudinally shiftable in avalve housing 49 detachably mounted upon the intermediate member 12.This valve housing has an air pressure supply connection 50 at thecenter, communicating with a pair of branch passages 51 and 52, and alsohas a pair of transfer pipes 53 and 54 communicating with the respectiveends of the main control valve V-l. Furthermore,-vent connections 55 and56 are provided at the respective ends of pilot valve housing 49.

With the pilot valve unit V-2 thus located between the two valve bodies,and the valve member 48 thereof extending parallel to the actuating rod,the shifting of the valve member, according to one embodiment, iseffected by a pair of opposedly arranged pusher pins 57 and 58 engagingrespective ends of the valve member. The pusher pins extending parallelto the actuating rod, are slidable longitudinally in the wall of therespective pump housings, and are mounted in pressure-sealedrelationship therewith, in a manner furthermore to be described belowand in connection with the detail showing thereof in FIG. 4. At the endof each pumping stroke, as effected by the main valve unit V-l, theclamping plates of a respective diaphragm will through the associatedpusher pin move the pilot valve member between the end positions shownin FIGS. 1 and 2, thereby maintaining the continuity of the pumpingoperation described as follows:

In the condition of FIG. 1, the actuating rod 37 is shown during itsmovement to the left, with both the pilot valve member 48 and the mainvalve member 47 in their right hand end position. This represents thecondition where the pilot air supply from pipe 50 acting through passage51 and transfer pipe 53 has moved the main plug valve member 47 to theright hand end posi tion. Thus, the main air supply from pipe 44 throughpassage 44 and transfer pipe 42 will act upon the left hand diaphragmduring the pump delivery stroke coinciding with the pump intake strokeof the right hand diaphragm. It will be understood that during thispumping stroke to the left, the right hand actuating chamber 26 is beingvented through transfer pipe 43 and exhaust 46 of control valve V-l,while the right hand end of valve V-I is vented through pipe 54 andthrough the pilot valve V-2.

At the end of the stroke to the left, the clamping plate of the righthand diaphragm will engage pusher pin 58 causing the same to move thepilot valve member 48 to the opposite or left hand end position shown inFIG. 2, thus admitting pilot air pressure through pipe 54 to the righthand end of the main valve housing, which pressure moves the main valvemember to its left hand end position.

through pusher pin 57 shift the pilot valve member back to its FIG. 1right hand end position, thus initiating the next following operationcycle. It will be understood that during the pumping stroke to the rightin FIG. 2, the left hand actuating chamber 17 is vented through pipe 42and through the main valve unit V-l, while the left hand end of main.valve V-I is vented through pipe 53 and through the pilot valve unitV-2.

The intermediate portion of the pump in FIG. 3 provides a more detailedshowing of the mounting of the pilot valve unit v-2 in relation to theassociated pusher pins. In this arrangement, a pair of screw bolts 59and 60 indicate the manner in which this valve unit is detachably fixedto the intermediate connecting member 112. The left hand end E-ll of thepilot plug valve member in this valve unit through finger 61 contacts anadjustable stop nut 62 on pusher pin 57. Similarly, the right hand endE-2 of the plug valve member through finger 63 contacts an adjustablestop nut 64 on pusher pin 58.

The proper timing of the control system is readily attainable byadjusting the stop nuts 62 and 64 upon the threaded inner end portionsof the respective pusher pins. The effective length of the pumpingstroke is also adjustable by the setting of the stop nuts on the pusherpins, so that the pump can be operated, for example, either at higherfrequencies of the pumping cycle with a shorter stroke, or at lowerfrequencies with a longer pumping stroke.

As previously indicated, the pusher pins 57 and 58 are mounted insealing relationship to the respective pump housing sections, effectiveagainst the operating air pressure applied to the actuating chambers 17and A pressure-sealed mounting of the pusher pins is shown in theenlarged detail FIG. 4. Accordingly, the pusher pin 58 is slidable in aholder 65 also designated by its length L-l. This holder comprises apart 66 of length L2 providing a first guide bearing surface 67interrupted by a first sealing ring 68, and part 69 in the form of aflanged bushing fitted into part 66, and providing a second guidebearing surface 70 interrupted by a second sealing ring 71. A thirdsealing ring 72 is effective between parts 66 and 69 and the surroundingflanged member 12. The distance between the two guide bearing surfaces67 and 70 defines the length L-3 of an annular chamber 73 surroundingthe pusher pin. Slidably fitted into this chamber are a pair of annularshoulder portions 74 and 75 provided upon, or integral with the pusherpin, with a fourth sealing ring 76 provided between the two shoulderportions. The assembly of parts 66 and 69 containing the pusher pin isseated upon a shoulder 77 in the flanged end of member 12, and held inplace by a retainer flange 78 bolted to said flanged end.

In the mounting of this pusher pin, provision is made for the airpressure acting upon the end face area F1 of the pusher pin to bebalanced by the air pressure acting through ports 79 upon the annulararea F-2 of shoulder portion 74. Furthermore, an axial bore 80 in thepusher pin communicates through a radial passage 81 with dead space 73of chamber 73, providing a vent connection with the atmosphere.

When mounted in the manner of FIG. 4 the pusher pins are easily andsmoothly movable in both directions together with the associated pilotvalve member, irrespective of the pressure differential between the airpressure in the actuating chambers 16 and 25 and the outer atmosphere.

The air pressure supply for operating both the pump and the valves ofthe control system, is represented by the main air pressure supply line82. The branch pipe 50 through hand operated valve 50 provides the airpressure whereby the pilot valve V-2 actuates the main control valve V1.The branch pipe 44 supplies the air pressure whereby the main controlvalve V-l controls the operation of the actuating chambers 17 and 26.Aside from a hand controlled valve 44 the pipe 44 also has a constantpressure valve 44 whereby a desired pressure can be maintainedautomatically in the actuating chambers 17 and 26. Changes in thepumping speed can be effected by changing the settling of the constantpressure valve.

In another embodiment according to FIGS. and 6, the single control valveV-l of FIGS. 1 and 2 is replaced by a pair of identical control valveunits V-3 and V-4, while the arrangement and operation of the pilotvalve unit V-5 is identical to those of valve unit V-l in FIGS. 1 and 2.

The control valve unit V-3 comprises a valve housing 82 wherein avertical plug valve member 83 has upper and lower enlarged cylindricalend portions or plugs 84 and 85 respectively, interconnected by a stem86. A compression coil spring 87 surrounding the stem is confinedbetween the upper plug 84 and a shoulder 87 formed by the valve housing.The upper end of this valve housing has a pipe connection 88 with pilotvalve unit V-5 (functionally corresponding to pipe 53 in FIGS. 1 and 2),and cooperating with the upper end of plug valve member 83. The bottomportion of the valve housing is connected to an air supply pipe 89, aswell as to a transfer pipe 90 leading to the left hand pump actuatingchamber 16. Between these two pipe connections the valve housing has abottom vent opening or connection 91 cooperating with the lower end ofplug valve member 83.

Similarly, valve unit V-4 comprises a valve housing 92 wherein avertical plug valve member 93 has upper and lower enlarged cylindricalend portions or plugs 94 and 95 interconnected by a stem 96. Acompression coil spring 97 surrounding the stem is confined between theupper plug 94 and a shoulder 98 formed by the valve housing. The upperend of this valve housing has a pipe connection 99 with pilot valve unitV-5 (functionally corresponding to pipe 54 in FIGS. 1 and 2), andcooperating with the upper end 94 of plug valve member 93. The bottomportion of this valve housing is connected to an air supply pipe 100, aswell as to a transfer pipe 101 leading to the right hand pump actuatingchamber 26. Between these two pipe connections the valve housing has abottom vent opening or connection 102 cooperating with the lower end 95of plug valve member 93.

The two air supply pipes 89 and 100 are branches of a main air supplypipe 103 which has an automatic pressure control valve 104 for settingthe operating pressure in the two pump actuating chambers 17 and 26. Athird branch pipe 105 supplied the line air pressure to the pilot valveV-5, and may have a hand operated valve 106.

In the condition of FIG. 5 of the pumping cycle (functionallycorresponding to the condition of FIG. 1), the pilot valve member 48 hasbeen moved to the right hand end position by the clamping plate of theleft hand diaphragm l5 acting through pusher pin 5. Thus, air pressurefrom pipe acting through pilot valve V-5 and through pipe 88 will havemoved the main valve member 83 against the spring pressure to the lowerend position closing the exhaust or vent connection 91, while opening apassage 107 allowing air pressure to pass therethrough into the lefthand actuating chamber 17.

At the same time, the opposite right hand actuating chamber 26 is ventedthrough pipe 101 and passage 108 in valve housing 92, while valve member96 is spring-urged into the upper end position closing the air pressuresupply from pipe 100. The upper end of valve housing 92 is ventedthrough pipe 99 and through the pilot valve unit V-5.

At the end of the left ward pumping stroke resulting from the conditionof FIG. 5, the clamping plate of the right hand diaphragm 24 willthrough pusher pin 58 move the pilot valve member 48 to the FIG. 6 lefthand position, thereby reversing the respective flow directions in thesystem, as indicated by the various flow arrows therein. Consequently,air pressure is admitted from supply pipe 100 and through passage 108 invalve unit V-4 to the actuating chamber 26, causing the diaphragmassembly to be moved to the right.

At the same time, the opposite left hand actuating chamber 17 is beingvented through pipe 90 and passage 109 in valve unit V-3, since thespring 87 will have moved the valve member 86 to the upper end positionclosing vent connection 88 open through the pilot valve, while alsoopening a vent connection from the actuating chamber 17 through pipe 90and through passage 109 in valve unit V-3.

At the end of the pumping stroke resulting from the condition of FIG. 6,the clamping plate of the left hand diaphragm 15 will again throughpusher pin 57 move the pilot valve member back to the right hand endposition, thus to initiate the next pumping cycle.

In another embodiment of the control valve system as shown in FIGS. 7and 8, the combination of a main control valve unit V-6 and a pilotvalve unit V-7 is the same structurally and functionally as the one inFIGS. 1 and 2. The difference lies in the provision of the motiontransmitting means whereby the movements of the pilot valve member arederived from the diaphragm assembly, and which require the pilot valveunit V-7 to be mounted on a laterally overhanging bracket 109.

As shown in FIGS. 7 and 8, these motion-transmitting means comprise anupright stem 110 extending from the actuating rod 111 through a slot 112formed in the surrounding connecting member 113, so that the stem willmove back and forth in the slot together with the actuating rod. Afinger 114 extends from the upper end of the stem horizontally acrossthe pump axis, and across and above the pilot valve unit V-7.

By engaging a bridge member 115, the finger 114 extending throughhorizontal slot 116 will move the pilot valve member between respectiveend positions each time the finger 114 reaches a respective end of theslot. The depending shanks and 115" of the bridge member engagerespective ends of the valve member secured by respective set nuts 117and 118. The length of the pumping stroke may be varied by the provisionof adjustable end steps or abutment (not shown) on bridge member 115,cooperating with finger 114. A

pair of nuts 119 and 120 on finger 114 maintain the bridge member in theproper upright position.

FIGS. 9 to 13 further illustrate practical features embodied in thestructural implementation of a pump operable in the manner of thepumping cycle shown in the schematic FIGS. 1 and 2.

In this practical embodiment, referring to FIGS. 9 and 10, a horizontalintake pipe 121 extends along one side of the pump at a low level adistance d-1 below the axis of the pump, and having a lateral intakeopening 122 equidistant from its ends. The left hand end of this intakepipe has a flanged connection 123 with an elbow member 124 which has anupwardly directed leg which in turn is flange-connected to the undersideof a first ball valve unit 125. A lateral neck 126 of this ball valveunit located at the level of the pump axis, has a flange connection 127with a first short horizontal pipe member 128 extending transversely ofthe pump axis, and having a horizontal lateral neck concentric with thepump axis and flange-connected at 129 to the adjoining left hand outerend of the pump.

The opposite or right hand end of intake pipe 121 is connected to asecond intake ball check valve unit 130 through an elbow member 131, ina manner similar and symmetrical to the first ball check valve unit 125.A second horizontal transverse pipe member 132 connects this ball checkvalve l30'with the right hand end of the pump similar and symmetrical tothe opposite or first transverse pipe member 128.

Along the opposite side of the pump, at a high level a distance d-2above the pump axis, extends a horizontal discharge pipe 133 having alateral discharge opening 134 equidistant from its ends. The left handend of this discharge pipe has a flange connection 135 with the lateralneck 136 of a first discharge ball check valve unit 137 the bottom ofwhich is connected through an elbow member 138 to the first transversehorizontal pipe member 128. The opposite or right hand end of thedischarge pipe has a flange connection 139 with the lateral neck 140 ofa second discharge ball check valve unit 141 the bottom of which in turnthrough an elbow member 143 is connected to the second transversehorizontal pipe member 132.

The pump unit shown in FIGS. 9 to 11 is mounted and supported in apractical manner illustrated in FIGS. 12 and 13, whereby the inspectionof the two diaphragms is greatly facilitated.

To that end, the pump unit is supported upon a pair of parallelsupporting beams or steel profiles shown in the form of channel irons142 and 143. For example, in order to inspect the diaphragm in the righthand pump body, a simple procedure is merely to disconnect thequick-detachable couplings 144 and 145, as well as to disconnect theflanges 146 of the associated pump housing sections 147 and 148. Theassembly of parts thus disconnected are to the right of the severinglines XX, Y--Y and Z-Z indicated in the plan view of FIG. 11. Thisassembly may then be slid outwardly away while supported on the beams,thereby exposing the diaphragm 149 in the manner illustrated in FIGS. 12and 13.

The control valve unit V-l in FIGS. 1 and 2 is available from Mac ValvesInc., Detroit, Michigan, Model No. 2733. The pilot valve V-2 in the sameembodiment 6 is available from Mac Valves Inc., Detroit, Mich., ModelNo. 1808-l-08.

The two identical air pressure actuated control valve units V3 and V-4in FIGS. 5 and 6 are available from Mac Valves Inc., Detroit, Mich,Model No. 4444.

I claim:

1. A double-acting pressure-actuated diaphragm pump having a horizontalpump axis, which comprises a first pair of housing sections bolted toeach other to constitute a first pump housing,

a first pump diaphragm interposed between said housing sections, anddividing the housing into a first pumping chamber having first intakeanddischarge connections directed away from one another, and a firstactuating chamber having an opening concentric with the diaphragm,

a second pair of housing sections bolted to each other to constitute asecond pump housing,

a second pump diaphragm dividing said second pump housing into a secondpumping chamber having second intakeand discharge connections directedopposite to each other, similar to said first intakeand dischargeconnections and a second actuating chamber having an opening concentricwith the diaphragm,

a tubular connecting member rigidly interconnecting said pump housingsin axially aligned relationship, and so that said first and secondactuating chambers are located adjacent to each other, and that the pumphousing assembly is constituted of a pair of inner housing sectionsdefining the respective actuating chambers, and a pair of outer housingsections defining the respective pumping chambers,

an actuating rod interconnecting said first and sec ond diaphragms,coaxial with the pump axis and guided in said connecting member insealing relationship with each end thereof, providing a double diaphragmassembly whereby the pump delivery stroke of one diaphragm will coincidewith the pump intake stroke of the other diaphragm,

said pump consisting of an intermediate section comprising saidconnecting member and associated inner housing sections,

a first disconnectible subassembly unit comprising the first outerhousing section, a first upright intake check valve having a lateraldischarge neck connected to said outer housing section, and having abottom intake neck extending parallel to the pump axis, and towards theopposite end of the pump, and a first upright discharge check valvehaving a bottom intake neck connected. to said outer housing section,and having a lateral discharge neck extending parallel to the pump axisand towards said opposite end of the pump,

a second disconnectible subassembly unit opposite to said firstsubassembly unit, which comprises the second outer housing section, asecond upright intake check valve having a lateral discharge neckconnected to said outer housing section, and having a bottom intake neckextending parallel to the pump axis and towards the opposite end of thepump, and a second upright discharge check valve having a bottom intakeneck connected to said outer housing section, and a lateral dischargeneck extending parallel to the pump axis and towards said opposite endof the pump,

a first intermediate pipe header detachably interconnecting the intakenecks of the first and second intake check valves, and having intakemeans for both said intake valves,

and a second intermediate pipe header detachably interconnecting thedischarge necks of the first and second discharge check valves, andhaving discharge means for both said discharge valves, and trackstructure for supporting said first and second subassembly units, whendisconnected from said intermediate section, and retracted to allow forinspection of the respective diaphragms.

2. The pump according to claim 1, wherein said first intermediate pipeheader comprises an intermediate section including said pump intakemeans, one end section connected to said first intake valve, and havinga quick detachable coupling connecting its inner end with the adjacentend of said intermediate section, and another end section connected tosaid second intake valve, and having a quick detachable couplingconnecting its inner end with the adjacent end of said intermediatesection,

and wherein said second intermediate pipe header comprises anintermediate section including said pump discharge means, one endsection connected to said first discharge valve, and having a quickdetachable coupling connecting its inner end with the adjacent end ofsaid second intermediate section, and another end section connected tosaid second discharge valve, and having a quick detachable couplingconnecting its inner end with the adjacent end of said intermediatesection.

3. The diaphragm pump according to claim 1, wherein said intake pipeheader is spaced downwardly from the pump axis by means of elbow membersconnecting the bottom inlet openings of the inlet check valves with therespective adjacent ends of said first intermediate pipe header, andwherein said discharge pipe header is spaced upwardly from the pump axisby means of elbow members connecting the bottom inlet openings of thedischarge check valves with the respective outer housing sections.

4. The diaphragm pump according to claim 1, wherein said connectingmember has end flanges detachably connected to the associated innerhousing sections, said flanged member having a concentric recess at eachend, and sealing means contained in the respective-recesses.

5. The pump according to claim 1, with the addition a control valvesystem for maintaining the operating cycle of the pump, operativelyconnected to said first and second actuating chambers, and having apressure fluid supply connection, and a control member movable to oneend position effective to allow said control system to admit pressurefluid to the first of said actuating chambers, while allowing the secondactuating chamber to be vented, and movable to the opposite positioneffective to allow said control system to admit pressure fluid to thesecond actuating chamber, while allowing said first chamber to bevented, in the course of a pumping cycle, and actuating means for movingsaid control member between said end positions substantially insynchronism with the reciprocations of the diaphragm assembly, therebymaintaining the pumping cycle.

6. The diaphragm pump according to claim 5,

wherein said transmitting means comprise,

a first pusher pin parallel to said actuating rod, and mounted in theadjacent inner housing section in sealing relationship therewith, andadapted to transmit movement of the diaphragm assembly to said controlmember of the control valve system so as to move the same in onedirection at the end of one stroke of the pumping cycle,

and a second pusher pin parallel to said actuating rod, and mounted inthe opposite inner housing section, and adapted to transmit movement ofthe diaphragm assembly to said control member of the control valvesystem, so as to move the same in one direction at the end of the nextstroke of the pumping cycle.

35 7. The diaphragm pump according to claim 5,

wherein said control system comprises fluid pressure-actuated maincontrol valve means communicating with said actuating chambers, andoperable to admit pressure fluid to said actuating chambers and ventingsaid chambers in alternation,

V and a fluid-actuated pilot plug valve unit mounted in fixedrelationship to said connecting member, parallel to said actuating rod,and having a longitudinally reciprocable pilot plug valve memberinterposed between, and actuated by said pusher pins, so thatreciprocating movement imparted by said pusher pins to said pilot valvemember parallel to said actuating rod will cause said main control meansto operate the pumping cycle.

1. A double-acting pressure-actuated diaphragm pump having a horizontalpump axis, which comprises a first pair of housing sections bolted toeach other to constitute a first pump housing, a first pump diaphragminterpOsed between said housing sections, and dividing the housing intoa first pumping chamber having first intake- and discharge connectionsdirected away from one another, and a first actuating chamber having anopening concentric with the diaphragm, a second pair of housing sectionsbolted to each other to constitute a second pump housing, a second pumpdiaphragm dividing said second pump housing into a second pumpingchamber having second intake- and discharge connections directedopposite to each other, similar to said first intake- and dischargeconnections, and a second actuating chamber having an opening concentricwith the diaphragm, a tubular connecting member rigidly interconnectingsaid pump housings in axially aligned relationship, and so that saidfirst and second actuating chambers are located adjacent to each other,and that the pump housing assembly is constituted of a pair of innerhousing sections defining the respective actuating chambers, and a pairof outer housing sections defining the respective pumping chambers, anactuating rod interconnecting said first and second diaphragms, coaxialwith the pump axis and guided in said connecting member in sealingrelationship with each end thereof, providing a double diaphragmassembly whereby the pump delivery stroke of one diaphragm will coincidewith the pump intake stroke of the other diaphragm, said pump consistingof an intermediate section comprising said connecting member andassociated inner housing sections, a first disconnectible subassemblyunit comprising the first outer housing section, a first upright intakecheck valve having a lateral discharge neck connected to said outerhousing section, and having a bottom intake neck extending parallel tothe pump axis, and towards the opposite end of the pump, and a firstupright discharge check valve having a bottom intake neck connected tosaid outer housing section, and having a lateral discharge neckextending parallel to the pump axis and towards said opposite end of thepump, a second disconnectible subassembly unit opposite to said firstsubassembly unit, which comprises the second outer housing section, asecond upright intake check valve having a lateral discharge neckconnected to said outer housing section, and having a bottom intake neckextending parallel to the pump axis and towards the opposite end of thepump, and a second upright discharge check valve having a bottom intakeneck connected to said outer housing section, and a lateral dischargeneck extending parallel to the pump axis and towards said opposite endof the pump, a first intermediate pipe header detachably interconnectingthe intake necks of the first and second intake check valves, and havingintake means for both said intake valves, and a second intermediate pipeheader detachably interconnecting the discharge necks of the first andsecond discharge check valves, and having discharge means for both saiddischarge valves, and track structure for supporting said first andsecond subassembly units, when disconnected from said intermediatesection, and retracted to allow for inspection of the respectivediaphragms.
 2. The pump according to claim 1, wherein said firstintermediate pipe header comprises an intermediate section includingsaid pump intake means, one end section connected to said first intakevalve, and having a quick detachable coupling connecting its inner endwith the adjacent end of said intermediate section, and another endsection connected to said second intake valve, and having a quickdetachable coupling connecting its inner end with the adjacent end ofsaid intermediate section, and wherein said second intermediate pipeheader comprises an intermediate section including said pump dischargemeans, one end section connected to said first discharge valve, andhaving a quick detachable coupling connecting its inner end with theadjacent end of said second intermediate section, and another endsection connected to said secoNd discharge valve, and having a quickdetachable coupling connecting its inner end with the adjacent end ofsaid intermediate section.
 3. The diaphragm pump according to claim 1,wherein said intake pipe header is spaced downwardly from the pump axisby means of elbow members connecting the bottom inlet openings of theinlet check valves with the respective adjacent ends of said firstintermediate pipe header, and wherein said discharge pipe header isspaced upwardly from the pump axis by means of elbow members connectingthe bottom inlet openings of the discharge check valves with therespective outer housing sections.
 4. The diaphragm pump according toclaim 1, wherein said connecting member has end flanges detachablyconnected to the associated inner housing sections, said flanged memberhaving a concentric recess at each end, and sealing means contained inthe respective recesses.
 5. The pump according to claim 1, with theaddition of, a control valve system for maintaining the operating cycleof the pump, operatively connected to said first and second actuatingchambers, and having a pressure fluid supply connection, and a controlmember movable to one end position effective to allow said controlsystem to admit pressure fluid to the first of said actuating chambers,while allowing the second actuating chamber to be vented, and movable tothe opposite position effective to allow said control system to admitpressure fluid to the second actuating chamber, while allowing saidfirst chamber to be vented, in the course of a pumping cycle, andactuating means for moving said control member between said endpositions substantially in synchronism with the reciprocations of thediaphragm assembly, thereby maintaining the pumping cycle.
 6. Thediaphragm pump according to claim 5, wherein said transmitting meanscomprise, a first pusher pin parallel to said actuating rod, and mountedin the adjacent inner housing section in sealing relationship therewith,and adapted to transmit movement of the diaphragm assembly to saidcontrol member of the control valve system so as to move the same in onedirection at the end of one stroke of the pumping cycle, and a secondpusher pin parallel to said actuating rod, and mounted in the oppositeinner housing section, and adapted to transmit movement of the diaphragmassembly to said control member of the control valve system, so as tomove the same in one direction at the end of the next stroke of thepumping cycle.
 7. The diaphragm pump according to claim 5, wherein saidcontrol system comprises fluid pressure-actuated main control valvemeans communicating with said actuating chambers, and operable to admitpressure fluid to said actuating chambers and venting said chambers inalternation, and a fluid-actuated pilot plug valve unit mounted in fixedrelationship to said connecting member, parallel to said actuating rod,and having a longitudinally reciprocable pilot plug valve memberinterposed between, and actuated by said pusher pins, so thatreciprocating movement imparted by said pusher pins to said pilot valvemember parallel to said actuating rod will cause said main control meansto operate the pumping cycle.